题目描述
For the given sequence with n different elements find the number of increasing subsequences with k + 1 elements. It is guaranteed that the answer is not greater than 8·1018.
Input
First line contain two integer values n and k (1 ≤ n ≤ 105, 0 ≤ k ≤ 10) — the length of sequence and the number of elements in increasing subsequences.
Next n lines contains one integer ai (1 ≤ ai ≤ n) each — elements of sequence. All values ai are different.
Output
Print one integer — the answer to the problem.
输入格式
见题面 Input 部分
输出格式
见题面 Output 部分
样例输入
5 2
1
2
3
5
4
样例输出
7